Currently, in use of a battery, when the battery power is excessively low or for other abuse reasons, such as excessive battery internal resistance and excessive output power caused when the operation environment temperature of the battery is too low, the output voltage will become too low. If the battery power is sufficient, such a situation will not affect the battery system, however, if there is less battery power or an undervoltage process is too long, then the voltage will be less than a minimum discharge voltage, if such a phenomenon occurs for a long time, cycle lifetime and discharge efficiency of the battery will be seriously affected, and therefore, there is a need to provide undervoltage protection for the battery.
The existing battery undervoltage protection method is generally performed by setting a minimum undervoltage protection voltage value as a trigger point of enabling an undervoltage protection circuit, since the battery has large current impedance at a low temperature, the existing method is adopted in the case where the battery has much power, high current interception easily causes undervoltage protection in a short time, so that the majority of the power is not utilized efficiently and undervoltage protection for the battery cannot be performed flexibly.